On May 20, 1951, a major riot erupted at the the Utah State Prison located at the Point of the Mountain. In a well organized plan, four guards were surrounded as prisoners were returning to their cells from the recreation yard. Doors leading from the security building to the administration building were blocked by means of a large fire hose. Thus the rioting inmates gained complete control of the main security building. The convicts could not escape the prison’s corridor which was automatically sealed by electric locks once the riot began. Inmates vandalized the facility, breaking nearly every toilet bowl and wash basin. This incident involved 260 prisoners and was the worst riot to date in Utah history.

At 4:30 p.m., UHP dispatcher Paul Keller received a call from the prison which declared, "All hell has broken loose." Keller said, "They told us to send as many cars as possible." Within 15 minutes Highway Patrol cars from Salt Lake, Ogden, Provo, Price and Richfield were enroute. More than 60 members of the Utah Highway Patrol and nearly 100 officers from Salt Lake County Sheriff’s Office, Salt Lake City, Orem, Provo and Murray Police responded.

Inside-the greatest danger was to the four guards taken hostage by the rioting prisoners. Most guards had escaped as the riot was developing. Two other guards had locked themselves into a second story room. Prisoners used a table as a battering ram in an attempt to beat the door down. Several convicts confined to death row threatened to dispose of all hostages if it became necessary. The two trapped guards ripped two bed sheets into strips and made a rope. They then broke out the window and lowered themselves from the second floor to the ground near tower number three. Inmates also gained access to the prison hospital. All narcotics found were looted and distributed among the rioting prisoners. Inmates then destroyed electrical control panels which left the entire facility in darkness.

Outside-officers surrounded the prison and turned on their vehicle headlights to compensate for the loss of electricity. Officers were armed with shotguns, handguns, sub-machine guns, and tear gas. Low hanging clouds and a steady downpour lent an eerie atmosphere as red and white spot lights reflected through the fog. One patrolman cracked, "Let’s choose up sides and have this thing out." Following a four-hour standoff, the rioting prisoners returned to their cells. Prisoners had demanded the ousting of the deputy warden and the captain of the guards. The Utah Highway Patrol was given command of the prison for a short period of time by Governor J. Bracken Lee. Shortly after this riot, the UHP established a 10-man riot squad. They were trained in riot formations, tactical weapons, tear gas, baton tactics, and crowd control.

The 1951 riot was only the second time the Utah State Prison had to call upon outside help to put down a riot. The first incident occurred at the Sugarhouse Prison on December 3, 1945, when six "incorrigibles" broke out of their grade disciplinary section of the cellblock tier and released 30 other convicts. Then they broke a separating door giving the rioters complete control of the cellblock. More than 50 windows were broken. Reinforcements were called in from the Utah Highway Patrol and from several city police agencies. After nine hours of rioting, the convicts returned to their cells and officials regained control of the prison.

On February 6, 1957, five Utah State Prison inmates stabbed Lieutenant M. L. Coleman, a prison guard, during a late night basketball game. This incident was followed by another major riot. On February 7, 1957, members of the Utah Highway Patrol, Salt Lake County Sheriff’s Office and a score of prison officers moved into the prison to extinguish the riot. During this 14 hour riot, prisoners did approximately $50,000 in damage to the facility.

Sergeant Nick Thomas was one of the UHP officers assigned to enter and regain control of the prison. Moving in a wedge formation, troopers and prison guards moved down the main corridor checking and securing rooms. As they came to the end of the corridor, a large group of inmates had gathered to offer a final show of force.

The leader of the group was inmate Theodore Keener, 24, serving five years to life for assault with intent to commit burglary. Keener was one of the inmates who had stabbed Lieutenant Coleman. Keener started moving forward as the officers approached. Sergeant Thomas stepped forward, drew his .357 magnum revolver, and announced, "Step past that door and you’re dead." Deputy Warden John W. Turner stepped to Nick’s side and said, "Now, now Nick, we can talk this over." Sergeant Thomas replied, "That’s the trouble with your prison. Too much talk and not enough doing." One of the cons hollered to Keener, "You better turn around. He means what he says." Keener backed down and the riot was over.

The five prisoners who had stabbed Lieutenant Coleman were transferred to the Salt Lake County jail. Following an initial investigation, 17 additional inmates, labeled as "troublemakers" were transferred to the Salt Lake County jail. These inmates were loaded onto two buses and were guarded by 20 Salt Lake County Deputy Sheriffs. An additional 30 troopers in 15 UHP cars surrounded the buses as they moved north on state road 91 from the Point of the Mountain to the Salt Lake County jail.

Later, Warden Marcell Graham requested additional manpower from UHP Colonel Lyle Hyatt. The troopers were needed to supplement the prison staff following the resignation of eight prison guards at the conclusion of this riot. Prior to the riot, the guard staff at the State Prison consisted of 64 officers.